Spraying device for cleaning workpieces



July 1, 1969 w; HEROLD 3,452,935

SPRAYING DEVICE FOR CLEANING WORKPIECES Filed Feb. 24, 196"? 8 25"; I, l /2 251 LT im FIG. 2

INVENTOR.

W/LL Y HE ROI. D

Arron/Er:

United States Patent US. Cl. 239-533 5 Claims ABSTRACT OF THE DISCLOSURE The present invention relates to a spraying device for cleaning workpieces by directing a spray of pressurized liquid such as water thereupon.

The invention resides in means with which the closing and opening of a spray nozzle of the device is effected by controlling the feed of the pressurized cleaning liquid to the device.

The present application is a continuation-impart application, based upon pending application Ser. No. 453,- 109, filed May 4, 1965 and now abandoned.

The present invention relates to devices for surface cleaning of workpieces by spraying a cleaning liquid such as water under pressure upon the surfaces of work pieces to be cleaned, and more particularly, to spraying devices for descaling rolled or forged workpieces.

Spraying devices of the general kind above referred to usually comprise one or more spraying nozzles, depending upon the surface areas of the workpieces to be cleaned, and particularly on the width of the workpieces. When several nozzles are provided, the same are usually mounted on a common carrier connected to a supply of pressurized water. These nozzles are turned on or off individually or in groups. The control of the nozzles in spraying devices as heretofore known is effected by manually, mechanically or electromagnetically operable valves included in the supply line for the pressurized cleaning liquid. Such operation of the spraying device is cumbersome and time-consuming. Furthermore, downwardly directed nozzles in spraying devices as heretofore known have a tendency to continue to drip for some time after they are shut off.

It is an object of the invention to provide a novel and improved spraying device of the general kind above referred to which can be conveniently and tightly turned off upon completion of a spraying operation.

A more specific object of the invention is to provide a novel and improved spraying device of the general kind above referred to in which the closing and opening, respectively, of the spraying nozzle or nozzles of the device is effected by utilizing the pressure of the cleaning liquid itself.

Another more specific object of the invention is to provide a novel and improved spraying device of the general kind above referred to in which the closing or opening speed of the spraying nozzle or nozzles may be varied to avoid damage to the device.

The aforementioned objects, features and advantages and other objects, features and advantages of the invention are obtained by controlling the discharge of liquid through the nozzle of the spraying device by a control valve including a plunger, which is displaced by being subjected to differential pressures on its opposite sides. The plunger defines two chambers in a closed cylinder, one of said chambers including the discharge nozzle of 3,452,935 Patented July 1, 1969 the device. The plunger has on its side facingthe nozzle an extension, the end face of which matches the peripheral outline of the intake of the nozzle and which thus constitutes a closure member. The plunger is slideable between a nozzle closing limit position in which the end face of the extension engages the nozzle intake to close the same, and a nozzle opening limit position in which the other side of the plunger abuts against the respective end wall of the cylinder, or is closely adjacent thereto. As is evident, the end face of the plunger extension decreases the effective area of the respective side of the plunger in the nozzle closing limit position thereof by the area of said end face. A first conduit is connected to the cylinder chamber including the nozzle for feeding pressurized liquid into this chamber. A second conduit for feeding pressurized liquid is connected with the other cylinder chamber and a spring positioned in said other cylinder chamber biases the plunger toward its nozzle closing limit position. A valve is provided for selectively connecting the second conduit with the first conduit or the atmosphere.

Connection of the second conduit with the first conduit causes movement of the plunger into its nozzle closing limit position due to the combined action of the pressure of liquid now present in said other cylinder chamber, the spring and the pressure drop caused in the cylinder chamber including the nozzle due to the discharge of liquid through the nozzle. Connection of the second conduit with the atmosphere causes movement of the plunger into the nozzle opening limit position and retention in said position against the action of the spring due to the higher pressure now present in the cylinder chamber including the nozzle than in the cylinder chamber now connected with the atmosphere.

The invention will be more fully described in connection with the accompanying drawing, which shows a preferred embodiment of the invention by way of illustration and not by way of limitation.

In the drawing:

FIG. 1 is a diagrammatic sectional view of a spraying device according to the invention, the nozzle being shown closed;

FIG. 2 is a similar diagrammatic sectional view of the device, but showing the nozzle open.

The two figures of the drawing show only those components of the device which are essential for the understanding of the invention.

Referring now to the figures more in detail, the exemplified device comprises a spray nozzle 1 of suitable design formed in an end wall 1a of a closed cylinder 3. The end wall in which the nozzle is formed may be integral with the side wall of the cylinder, but is preferably detachably mounted in the same and secured to the end wall, for instance, by a screw connection. The use of a detachable nozzle has the advantage that nozzles having different discharge orifices can be used in the same device, as will be more fully explained hereinafter.

A differential plunger 2 is slideable in cylinder 3 to define two chambers 3a and 3b therein. The face side 2 of the plunger is fiat but the face side 2" has a cylindrical extension 211 protruding therefrom. The diameter of extension of 2a which constitutes a closure member, is such that it matches the diameter of the intake end of the nozzle. It is evident that the effective areas on the two sides of plunger 2 are equal when the plunger is in its nozzle opening position, as shown in FIG. 2, but that when the plunger is in the nozzle closing position, as shown in FIG. 1, the effective area of the plunger side 2" is decreased by the area of the end face of extension 2a in comparison with the effective area of the face side 2.

Plunger 2 has in its side facing cylinder chamber 3b an axial bore 2b in which is received a coil spring 15.

This spring abuts on one end against the bottom wall of bore 2b and is suitably secured on the other end to the end wall of the cylinder bounding chamber 3b. The spring urges the plunger into its position closing the nozzle, as is shown in FIG. 1. The depth of bore 2b and the length of spring 15 are so correlated that the spring is substantially fully within the bore when the plunger is in the nozzle opening limit position, as is shown in FIG. 2. Placement of the spring in the bore of the plunger has the advantage that a spring with comparatively many turns can be used. Such spring has a soft spring characteristic and a shallow curve of increase of the spring force when it is compressed. It has been found that a spring of this type is particularly suitable for the purpose. A further advantage of placing the spring in the bore is that a lateral bending-out or kinking of the spring when the same is being compressed, is prevented. Moreover, the total length of the device can be held at a minimum and the mass of the plunger is also reduced to a minimum, thereby reducing the force required for displacing the plunger.

As is evident from the foregoing description, differential plunger 2 controls nozzle 1 and will either open or close the same, depending on the position of the plunger in the cylinder.

A high pressure pipe 5, which should be visualized as being connected to a suitable source of pressurized water or other pressurized cleaning liquid, is connected through a bushing 4 to the cylinder chamber 3a. The connection of pipe 5 with cylinder chamber 3a is so placed that the line is open in any position of the plunger within the cylinder.

The opposite cylinder chamber 3d is connected by a pipe 8 to a control valve 6 of conventional design. This valve is further connected by a pipe 8 to the pressure pipe 5 and by a pipe 10 to the atmosphere. A receptacle or sump 9 may be provided adjacent to the discharge end of pipe 10. As is evident, pipe 8' can be connected by valve 6 either to pipe 8, as is shown in FIG. 1 or to pipe 10, as is shown in FIG. 2 by appropriately turning a control member 6a of valve 6. A preferably adjustable throttle valve 11 may be included in pipe 10.

The function of the device as hereinbefore described, is as follows:

Let it be assumed that the valve control member 6a is set as shown in FIG. 1 and that plunger 2 is shown in the position of FIG. 1, that is, in the position in which the plunger extension 2a closes nozzle 1 so that there is no discharge of liquid through nozzle 1. The pressure in cylinder chamber 3b then corresponds to the pressure of liquid fed into the chamber via pieces 5 and 8, control valve 6 and pipe 8. The same liquid pressure is supplied to chamber 311, but the effective area of plunger side 2" is now less than the effective area of plunger side 2' due to extension 2a abutting against the intake side of the nozzle thereby eliminating the face side of the extension as an effective area. Accordingly, a downwardly directed pressure force acts upon the plunger, holding the same in the nozzle closing position. The retention force acting upon the plunger may be amplified by dimensioning spring 15 so that it exerts a downward pressure upon the plunger even if the same is in the closing position of FIG. 1.

Let it now be assumed that it is intended to open the nozzle, that is, to move the plunger from the position of FIG. 1 into the position of FIG. 2. For this purpose, control member 6a is turned from the position of FIG. 1 into the position of FIG. '2. As is evident, the pressure in chamber 3b is now relieved via pipe 8, valve 6 and open-ended pipe 10. Accordingly, the liquid pressure in chamber 3b will force the plunger into the position of FIG. 2 against the action of spring 15, which, of course, must be appropriately dimensioned.

A sharp impact of the plunger 2 against the top end wall of c linder 3 can be readily gushioned by adjusting throttle valve 11 so that the pressure in chamber 3b is not too abruptly relieved.

When it is desired to close the nozzle again, valve member 6 is returned to the position of FIG. 1.

As is evident from an examination of the figures, the effective areas of plunger sides 2' and 2" are equal in substantially all plunger positions other than the position of FIG. 1, since the face end of extension 2a constitutes in all such positions part of the effective area of plunger side 2". As is further evident, the pressures in the two chambers as caused by the feed of pressurized liquid through pipe 5 are the same. However, two downwardly directed forces act upon the plunger, causing the same to move from the position of FIG. 1 into the position of FIG. 2. One of these forces is provided by the so-called nozzle effect. As is well known, a discharge of a pressurized liquid or other fluid through a nozzle causes a pressure drop in the space above the intake end of the nozzle. Accordingly, the pressure in cylinder 3a becomes lower than the pressure in cylinder chamber 3b, not withstanding the equal effective areas on the opposite sides of the plunger. The second downwardly directed force is supplied by spring 15. Tests have shown that the plunger will move rapidly and completely into its closing position, thus abruptly stopping the discharge of liquid through the nozzle when desired.

A spraying device as manufactured by the applicant has a cylinder with an inner diameter of 28 mm. and a plunger with an outer diameter closely fitting the inner diameter of the cylinder. The end wall In in which the nozzle 1 is formed may have the same dimensions for all pressures and nozzle dimensions that are used in practice. The coil spring 15 as used in applicants device has in its compressed condition, that is in the condition shown in FIG. 2, a spring force of about 30 kp.

The nozzles have preferably a discharge diameter of 2 to 5.2 mm. The water pressure in pipe 5 depends obviously upon the available supply, but it is generally between 50 and 180 atmospheres. Pressures between and atmospheres have been found to be particularly suitable. The closing force produced by the nozzle effect depends, of course, upon the water pressure and the diameter of the outlet end of the nozzle. The nozzle effect increases with water pressure and diameter of the nozzle discharge end. For instance, within the aforestated range of the nozzle opening and a water pressure of 50 atmospheres, the closing force caused by the nozzle effect is between 1.9 and 16 kp.; at a pressure of about 100 atmospheres between 4 and 31 kp., and at a pressure of about 130 atmospheres between 5 and 39.5 kp. As previously explained, the pressure caused by the nozzle effect is supplemented by the closing pressure of spring 15 which is initially 30 kp. in applicants device.

As is apparent from the foregoing description, the same pressurized liquid which is used for descaling or otherwise cleaning workpieces by being sprayed through the nozzle upon the workpieces, is also used to control the opening and closing of the nozzle, and such control is very simply effected by turning valve control member 6a into one direction or the other.

Control valve 6 may, of course, be opened directly to the atmosphere, but is generally preferable to provide the discharge pipe 10 and the adjustable throttle valve 11 to cushion the impact of the plunger upon the respective cylinder end wall, as previously described.

Operation of control member 611 may be manually effected, but it is generally preferable to provide an automatic control. Such automatic control may be made dependent upon the volume of the pressurized cleaning liquid, which in turn is determined by the dimensions and the conditions of the workpieces to be descaled or otherwise cleaned.

In actual practice, several nozzles associated with control means, as shown in FIGS. 1 and 2, are generally used. These nozzles are turned on and off individually or in,

groups, depending upon the width and other dimensions of the workpieces to be treated.

Automatic control devices suitable for the purpose are well known in the art and do not constitute part of the invention. They may, for instance, include controls by photo cells or light variores.

While the invention has been described in detail with respect to a certain new preferred example and embodiment of the invention, it will be understood by those skilled in the art, after understanding the invention, that various changes and modifications may be made without departing from the spirit and scope of the invention, all such changes and modifications in the appended claims.

I claim:

1. A descaling device for rolled or forged workpieces by directing a spray of a pressurized cleaning liquid thereupon, said device comprising in combination:

(a) a spraying nozzle;

(b) a closed cylinder, said nozzle being formed in one end wall of said cylinder with its discharge end facing outwardly and its intake end inwardly;

(c) a plunger slideable within the cylinder to define two chambers therein and having an extension on its side facing the nozzle intake, said plunger being slideable between a nozzle closing limit position in which the end face of the extension is seated upon said end face thereby closing the nozzle intake and a nozzle opening limit position in which the plunger is Withdrawn from said nozzle intake, the effective area of the side of the plunger having the extension being decreased by the area of the end face of the extension in the nozzle closing position of the plunger and being equal to the other side of the plunger in the nozzle opening position;

(d) a first conduit for feeding pressurized cleaning liquid into the cylinder chamber including the nozzle intake, said first conduit being connected to said chamber at a point thereof in which the conduit is open in all positions of the plunger;

(e) a second conduit connected to said other cylinder chamber for feeding pressurized cleaning fluid thereto;

(f) a spring in said cylinder positioned between the other end wall of the cylinder and the plunger to bias the latter toward the nozzle;

(g) a third conduit connected at one end to the atmosphere; and

(h) a two-way control valve means connected to said first conduit and to said second conduit and also connected to the other end of said third conduit, said control valve means including a movable control member connecting in one position the second conduit to the first conduit and closing in a second 5 position said connection and connecting the second conduit to the third conduit, connection of the second conduit with the first conduit supplying said other cylinder chamber with pressurized liquid thereby causing movement of the plunger into the nozzle closing limit position due to the combined action of the pressure built up in said other cylinder chamber, the pressure drop caused in said one cylinder chamber due to the discharge of liquid through the nozzle and the spring pressure, and connection of the second conduit with the atmosphere causing movement of the plunger into the nozzle opening limit position and retention in said position against the action of the spring due to the higher pressure now prevailing in the cylinder chamber including the nozzle intake.

2. A spraying device according to claim 1 wherein said plunger has in its side facing said other cylinder end wall an axial bore, and wherein said spring is a coil spring extended into said bore abutting against the bottom there- 25 of and secured at its other end to said other cylinder end wall.

3. A spraying device according to claim 2 wherein the spring in its substantially compressed condition is substantially completely accommodated in said bore.

4. A spraying device according to claim 1 wherein the end wall of the cylinder including the nozzle is releasably mounted in the side wall of the cylinder.

5. A spraying device according to claim 1 wherein an adjustable throttle valve is included in said third conduit. 35

References Cited UNITED STATES PATENTS 3,155,365 11/1964 Hartung et al.

FOREIGN PATENTS 18,437 9/1963 Japan. 427,367 11/ 1947 Italy. 436,830 6/1948 Italy.

ALLEN N. KNOWLES, Primary Examiner.

MICI-MEL Y. MAR, Assistant Examiner.

US. Cl. X.R. 251-31, 63 

